Cyperus distans L. f., Cyperaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Common name(s): [more details]

Chinese: shu sui suo cao

English: slender cyperus, souchet distant

Habit:  sedge

Description:  "Perennial, with small cormlike rhizome; culms solitary or few together, often rather slender, 35-100 cm tall, triquetrous, thickened at base; leaves shorter than culm; blades linear, 4-6 mm broad, weakly folded, herbaceous; sheaths rather elongated, light brown; corymb compound to decompound; leafy bracts 4-6, the lower 2 or 3 surpassing the corymb; rays 5-10, 1-15 cm long, patent; secondary corymbs with sort raylets or bearing 8-20 spikelets; spikelets divergent, linear, 8-40 mm long, 0.8-1 mm broad, cylindric, 8-32-flowered; glumes distantly disposed on a weakly zigzag rhachilla, elliptic, 1.8-2 mm long, obtuse at apex, membranous, sanguineous-brown on both sides, 3-5-nerved near keel, white-hyaline on upper margin, the keel greenish, hardly reaching the glume apex, the base decurrent along rhachilla, forming caducous white-hyaline wings; achenes oblong to oblong-elliptic, 3-sided, about 2/3 as long as glume, maturing dark brown, minutely punctulate; style short; stigmas 3; stamens 3" (Smith, 1979; pp. 247-248).

Habitat/ecology:  "A pantropical sedge occurring in wet grasslands and along waysides" (Wiggins & Porter, 1971; p. 802).

In Fiji, "probably a naturalized adventive...where it occurs near sea level on roadsides and cultivated land and in pastures" (Smith, 1979; pp. 247-248). In Papua New Guinea, "A weed of  roadsides, gardens, plantations and pastures; more troublesome in the wetter highland areas" (Henty & Pritchard, 1975; p. 31).

Propagation:  Seed

Native range:  Pantropical.

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Fiji Fiji Islands	Viti Levu Island	introduced invasive	Smith, Albert C. (1979) (pp. 247-248) Vouchers cited: Greenwood 756, DA 8449, DA 9931, DA 8683, DA 3806, DA 7677, DA 8612, Greenwood 1104, DA 428
Palau Palau (main island group)	Babeldaob Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 66)
Palau Palau (main island group)	Koror Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 66)
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)	invasive	Henty, E. E./Pritchard, G. H. (1975) (p. 31) In New Guinea, widespread, from low altitudes to over 2000 m.
Philippines Philippine Islands	Philippine Islands		Hafliger, E. (1092) (p. 17)
Solomon Islands Solomon Islands	Solomon Islands		Swarbrick, John T. (1997) (p. 90)
Solomon Islands Solomon Islands	Solomon Islands	native	Hancock, I. R./Henderson, C. P. (1988) (p. 62)

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Australia Australia (continental)	Queensland	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
China China	China (People's Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
China China	Hong Kong	native	Wu, Te-lin (2001) (p. 309) In paddy fields and other wet places.
Colombia Colombia	Colombia (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Ecuador (Mainland) Ecuador	Ecuador (Republic of) (continental)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Honduras Honduras	Honduras (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Indonesia Indonesia	Indonesia (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Malaysia Malaysia	Malaysia (country of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Mexico Mexico	Mexico (United Mexican States)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Nicaragua Nicaragua	Nicaragua (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Perú Perú	Perú (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Singapore Singapore	Singapore (Republic of)	uncertain if introduced invasive	Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009) (p. 31) Weed of uncertain origin
Vietnam Vietnam	Vietnam (Socialist Republic of)		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 114)

Indian Ocean
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Mauritius Mautitius Islands (Mauritius and Rodrigues)	Mauritius Island		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 114)

Additional information:
Additional online information about Cyperus distans is available from the Hawaiian Ecosystems at Risk project (HEAR).

Information about Cyperus distans as a weed (worldwide references) may be available from the Global Compendium of Weeds (GCW).

Taxonomic information about Cyperus distans may be available from the Germplasm Resources Information Network (GRIN).

References:

Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. 2009. A checklist of the total vascular plant flora of Singapore: native, naturalised and cultivated species. Raffles Museum of Biodiversity Research, National University of Singapore. 273 pp.

Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce. 1987. A geographical checklist of the Micronesian monocotyledonae. Micronesica 20:1-126.

Hafliger, E. 1092. Monocot Weeds 3. CIBA-GEIGY Ltd., Basle, Switzerland. 132 pp. plus plates.

Hancock, I. R./Henderson, C. P. 1988. Flora of the Solomon Islands. Research Bulletin No. 7. Ministry of Agriculture and Lands, Honiara. 203 pp.

Henty, E. E./Pritchard, G. H. 1975. Weeds of New Guinea and their control. 2nd edition. Department of Forests, Division of Botany, Botany Bull. No. 7. Lae, Papua New Guinea. 180 pp.

Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. 1979. A geographical atlas of world weeds. John Wiley & Sons, New York. 391 pp.

Smith, Albert C. 1979. Flora Vitiensis nova: a new flora of Fiji. National Tropical Botanical Garden, Lawai, Kauai, Hawaii. Volume 1. 494 pp.

Swarbrick, John T. 1997. Weeds of the Pacific Islands. Technical paper no. 209. South Pacific Commission, Noumea, New Caledonia. 124 pp.

U.S. Dept. Agr., Agr. Res. Serv. 2011. National Genetic Resources Program. Germplasm Resources Information Network (GRIN). Online searchable database.

Wiggins, I. L./Porter, D. M. 1971. Flora of the Galapágos Islands. Stanford University Press. 998 pp.

Wu, Te-lin. 2001. Check List of Hong Kong Plants. Hong Kong Herbarium and the South China Institute of Botany. Agriculture, Fisheries and Conservation Department Bulletin 1 (revised). 384 pp.

Zhengyi, Wu/Raven, Peter H./Deyuan, Hong. 2011. Flora of China (online resource).